Precision spraying apparatus for sheet-like articles



D. BARNES May 5, 1970 PRECISION SPRAYING APPARATUS FOR SHEET-LIKE ARTICLES Filed July 24. 1967 2 Sheets-Sheet 1 M l I' II I IA L IIIIL IIIIL mvzmoa DEREK BARNES Li uo IIIIL lllll 1 ATTORNEYS y 5, 1970 D. BARNES 3,509,851

PRECISION SPRAYING APPARATUS FOR SHEET-LIKE ARTICLES Filed July 24. 1967 2 Sheets-Sheet 2 INVINTOI [T- 7- b. DEREg BARNES United States Patent US. Cl. 118-316 24 Claims ABSTRACT OF THE DISCLOSURE Apparatus for spraying a uniform coating of liquid on either or both of the surfaces of sheet-like articles, and particularly articles that are liable to wrinkle before or during the spraying operation. The apparatus includes spraying means, and means for moving the articles past the spraying means while retaining said articles in the flat state so that the entire surface being sprayed is maintained substantially equidistant from the spraying means as it passes the latter. The apparatus also preferably includes shielding means for the spray guns, and shielding means for confining liquid overspray rebounding from the articles.

BACKGROUND OF THE INVENTION This invention relates to apparatus for the precision spraying of liquid, such as liquid glue, evenly on to One or both surfaces of sheet-like articles, such as veneer cores for plywood. This apparatus is particularly designed for spraying glue on the core veneer and, for the sake of convenience, will be described in connection with this purpose, but it is to be understood that the apparatus can be used for spraying any liquid, such as paint or other coating materials, onto sheet-like articles where it is desired to produce an even covering or coating, and particularly for articles that are liable to wrinkling.

The core veneers to which glue is applied usually have a more constant and greater measurement in the direction parallel to the grain than across said grain. Therefore, it facilitates handling if these pieces are moved through the spray zone in the direction of their constant and greater measurement, but in this arrangement there is a tendency for the veneers to develop a waviness across the grain so that sections transversely of the veneers diverge upwardly and downwardly from the flat general plane of travel. This prevents an even application of the glue to the veneer surfaces which is essential for proper and eflicient production of plywood. The problem is to get each veneer sheet substantially flat and to maintain it in this condition while the glue is sprayed onto the surfaces thereof. Thus, the veneers have to be held during the spraying operation, and the difficulty is to do this without interfering with the spraying, while being sure that the entire surfaces being sprayed are covered, that the application of the glue is even throughout the entire surfaces of the veneer, and without disturbing or smearing the glue after it has been applied to the surfaces,

SUMMARY OF THE INVENTION Spraying apparatus according to the present invention includes a plurality of laterally-spaced upper and lower thin wires arranged in upper and lower common planes and extending longitudinally of a path along which the sheet-like articles are to be moved. The upper and lower wires are vertically spaced apart sufliciently to enable the articles to be moved therebetween and to form said path having an entrance at one end of the wires and an exit at the opposite end thereof. First pressure means near the path entrance grips the articles to move them between the upper and lower wires, while second pressure means adjacent the path exit grips the articles to draw out from between the wires. The apparatus includes spraying means adjacent the wires to spray liquid on the articles as the latter are moved along the path between the wires. The spraying means is preferably in the form of one or more spray guns each having a nozzle directed towards the article path. Although if desired only one surface of each article may be sprayed, the ap paratus usually is designed to spray liquid onto both of the surfaces of the sheet-like articles. The preferred form of spraying apparatus includes shielding means for protecting the spray guns from the spray, and additional shielding means for confining liquid overspray rebounding from the articles.

The first pressure means is preferably in the form of a pair of upper and lower pressure rolls, one or both of which being driven, and having resilient peripheral surfaces and a nip therebetween transversely aligned with the entrance of the article path. The second pressure means is preferably in the form of set of upper and lower serrated gripping members extending transversely of the path with one set spaced from the other to enable serrations of the gripping members to grip the upper and lower surfaces of the articles at the exit end of the path. The first and second pressure means are usually spaced apart in distance less than the length of the shortest individual article to be sprayed.

The upper and lower wires are closely spaced together so that the veneers which are substantially flat when they are directed to the path entrance are maintained in that condition by the wires during the spraying of the article surfaces. These wires are very thin, something of the Order of 0.020 inch in diameter, and the transverse spacing of the wires is usually around 1 inch, although this can be varied. The wires retain the veneers at a fixed distance from the spray guns so that the top and bottom surfaces of the veneers are simultaneously sprayed evenly throughout the areas thereof. The small diameter of the wires does not interfere with the required uniformity of the glue sprayed on the surfaces. The first pressure means drives the veneers into the path between the wires, while the second pressure means draws the coated veneers out of said path. As the veneers are contacted only by the serrations of the gripping members, the glue is not smeared or interferred with at this time.

The apparatus is improved by providing means to depress or raise any veneer portions thereof that might be sticking up or down as the veneers approach the serrated gripping members. This is accomplished at either or both the path entrance and exit by an upper and lower curved or inclined edges converging towards each other in the direction of movement of the articles and having spaces therebetween aligned with the path entrance and path exit, respectively. Sometimes a strip of wood at the leading edge of a veneer, owing to spliting of the wood, will spring up or down between the wires, and in this case, the inclined edges at the exit will depress or raise the strip so that it will move between upper and gripping members. Without these inclined edges in this situation, the strip may engage an upper or lower serrated member and cause the veneer to be split from end to end thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a reduced diagrammatic side elevation of a preferred form of precision spraying apparatus in accordance with this invention,

FIG. 2 is a combined end elevation and sectional view of the apparatus, taken on the line 22 of FIG. 1,

FIG. 3 is an elevation of the opposite end of the apparatus, e 7

FIG. 4 is a vertical longitudinal section taken on the line 4-4 of FIG. 2,

FIG. 5 is a horizontal section taken on the line 5--5 of FIG. 2, and

FIG. 6 is an enlarged sectional view taken on the line 6-6 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, 10 is a preferred form of precision spraying apparatus particularly designed for spraying glue on to the upper and lower surfaces of veneers to be used as core sheets in plywood panels. However, the apparatus can be used to spray other liquids on sheet-like articles. Although this apparatus is used for spraying the upper and lower surfaces of the veneers, it can be used as is to spray either of said surfaces alone, or it can be construcer to spray only one surface.

Apparatus 10 includes an upper row of spray guns 12, each having a nozzle 13 projecting downwardly therefrom. Although guns 12 are shown mounted outside the main portion or casing of the apparatus with the nozzles 13 inside said apparatus, it will be understood that the guns can be completely enclosed within the apparatus, in which case it would be preferably removably tomount them so that they can be taken out for inspection and repair.

A row of lowerguns 16 is provided below guns 12, each gun having a nozzle 17 projecting upwardly therefrom. Guns 16 are mounted in the same way as guns 12. Nozzles 13 and 17 project towards each other, but are spaced apart'so that sheet-like articles, such as core veneers 20, to be sprayed can be moved along the path 22 extend between said nozzles.

Suitable means are provided for moving veneers 20 along path 22 between gun nozzles 13 and 17 while maintaining said veneers in substantially fiat condition. This means includes a plurality of laterally-spaced upper thin wires 25 arranged in a common plane and extending longitudinally of path 22, and a plurality of laterally-' spaced'lower thin wires 27 arranged in a common plane and extending longitudinally of said path. Said upper and lower wires are spaced apart vertically, as indicated at 29, a distance substantially equal to the thickness of the articles or veneers to be handled in the apparatus. This distance may be the actual thickness of the veneers, or a little greater than said thickness, but the wires must be close enough together to keep all portions of each veneer sheet practically flat as it moves through the apparatus so that said portions between gun nozzles-13 and 17 will be substantially equally spaced therefrom. The wires are maintained parallel to each other and extending longitudinally of path 22 in any conventional manner, and the ends of these wires are conveniently anchored, and one be later described.

Spray guns 13 and 17 may be of any desired type, but they preferably are the internal air-mix type, and guns 12 have a glue header 32, an atomizing air header 33 anda control air header 34 connected thereto by suitable tubing. Spray guns 16 have a glue header 37, an atomizing'air header 38, and a control air header 39 connected thereto by suitable tubing. The operation of this type of gun is well known, and does not require further description herein.

Suitable shielding is provided for the spray guns and to confine overspray, which is, glue spray that bounces Off the veneers or core pieces and/or travels somewhat laterally from the gun nozzles. A casing 42 is provided for this purpose, and includes similar upper and lower sections 44 and 45. i

Upper section 44 of the casing includes an inner shield 47 which is roughtly V-Shaped in cross section. The

way of doing this will nozzles 13 of guns 12 project downwardly from a lower '"wall 48 of the shield, and this shield has side walls 49 and 50 which extend upwardly and outwardly from wall 48, as clearly shown in FIG. 4. Shield 47 completely separates guns 12 from inside casing section 44, while the nozzles 13 of these guns project downwardly from the shield within the casing.

An outer shield 53 is provided in order to confine the overspray from the veneers and the upper guns. Outer shield 53 has side walls 55 and 56 extending upwardly from lower edges 58 and 59, respectively, located immediately above path 22. Walls 48, 49 and 50 of inner shield 47 actually form the top of outer shield 53.

Troughs 62 and 63 are formed along the lower edges 58 and 59 of shield 53 inwardly of said edges. Troughs 62 and 63 are shaped to form funnels 64 and 65 which narrow down towards path 22 in the direction of movement of the veneers therealong, said direction being indicated by arrow 66 in FIG. 4.

Any glue deposited on the inner surfaces of the walls of shield 53 runs down said surfaces into troughs 62 and 63. Glue deposited on the inner surfaces of the walls of shield 47 either drops down into these troughs or is directed onto the upper surfaces of the veneers travelling along the path. The glue drains from troughs 62 and 63 at both ends thereof either into a trough or suitable pipe means extending out of the apparatus, or into a bottom drain section.

The lower section 45 of casing 42 is provided with inner and outer shields 70 and 71 which are similar to shields 47 and 53, but inverted relative thereto. Inner shield 70, which is of substantially inverted V-shape in cross-section, has an upper central transverse wall 73 through which nozzles 17 of lower guns 16 extend, and side walls 74 and 75 inclined downwardly and outwardly from wall 73. Outer shield 71 has sidewalls 78 and 79 which are connected at the lower ends to shield walls 74 and 75, and project upwardly therefrom to upper edges 81 and 82 located immediately below path 22. Said upper edges are bent away from each other to form funnels 83 and 84 which narrow down in the direction of movement of the veneers along the path 22. Any glue deposited on the inner surfaces of the walls of shields 70 and 71 runs down these walls into troughs 86 and 87 from which drain pipes 88 and 89 extend.

A pair of closed upper exhaust hoods 93 and 94 are formed on the outer surface of outer shield walls 55 and 56, and open downwardly towards path 22 at 95 and 96. Stacks 98 and 99 extend from the tops of hoods 93 and 94 either to atmosphere outside the building in which the apparatus is located, or to suitable separating apparatus, not shown, for separating the fine glue from the atomized air.

A pair of closed lower exhaust hoods 104 and 105 are mounted on the outer surfaces of lower shield walls 78 and 79 and open upwardly towards path 22 at 106 and 107. If desired, drains 110 and 111 may extend away from the bottoms of hoods 104 and 105.

By referring to FIG. 2, it will be seen that casing 42 is provided with removable side walls 115 and 116, and these walls close the ends of inner shields 47 and 70, outer shields 53 and 71, and exhaust hoods 93, 94, and 104, 105. The upper hoods 93 and '94 are in communication with lower hoods 104 and 105 through openings 95, 106 and 96, 107 so that exhaust pipes 98 and 99 can serve the upper and lower hoods, but if desired, separate exhaust pipes 119 and 120 may be provided for the lower hoods.

Upper air jets 123 and 124 are provided in hoods 93 and 94 and are directed respectively towards hood openings 95 and 96 so as to direct air through these openings into the outer shield to prevent atomized glue from entering the hoods. Similarly, lower air jets 127 and 128 are provided in hoods 104 and 105 and are directed towards openings 106 and 107 thereof. These direct streams of air through the openings into the adjacent outer shield to prevent atomized glue from entering the hoods.

As stated above, the ends of wires 25 and 27 are mounted in any convenient manner, and a preferred way of doing this is illustrated in the drawings. The bottom 132 of hood 94 and the top 133 of hood 105 diverge away from each other in the direction opposite to the movements of the veneers along path 22 to form an entrance funnel 135, while the bottom 137 of hood 93 and the top 138 of hood 104 diverge away from each other in the direction of movement of said veneers to form an exit funnel 140 for path 22. Inner edges 141 and 142 of bottom 137 and top 138 of hoods 93 and 94 diverge away from each other in the direction opposite to the movement of the veneers to form a funnel 143 with the large end thereof opening in said opposite direction.

Upper wires 25 extend along the top of path 22, upwardly along inclined bottom 132, through laterallyspaced notches 144 in a bar 145 to ends of springs 146, which are anchored at their opposite ends to a bar 147. Similarly, the opposite ends of wires 25 extend along upwardly inclined bottom 137 through a notched bar 149 to ends of springs 150, the opposite ends of which are anchored to a bar 151. The notches of bars 145 and 149 keep the wires parallel to each other, while springs 146 and 150 permit a limited amount of longitudinal movement to each of these wires. If desired, either or both of these springs may be omitted.

Lower wires 27 are preferably mounted in the same manner as upper wires 25. FIG. 4 shows the ends of wires 27 passing through notched bars 155 and 156, and connected to springs 158 and 159.

First pressure means 165 is provided adjacent path entrance 135 for moving veneers 20 into and along path 22, and second pressure means 167 is provided near exit 140 for drawing the veneers along and out of said path. Pressure means 165 and 167 are spaced from each other a distance less than the length of the shortest piece of veneer to be handled by this apparatus.

First pressure means 165 comprises upper and lower pressure rolls 170 and 171, said rolls being formed of any suitable material, but preferably having resilient peripheral surfaces 173 and 174, formed of rubber, plastic material or the like. These rolls have a nip 176 therebetween extending across the article path and aligned with the entrance thereof. Either or both of these rolls is or are driven by suitable means.

Second pressure means 167 comprises a set of upper, laterally-spaced serrated disc rolls 177 fixedly mounted on a shaft 178, and a set of lower, laterally-spaced serrated disc rolls 180 fixedly mounted on shaft 181. The shafts and disc rolls are mounted in exit funnel 140 so that veneers 20 emerging from path 22 pass between the upper and lower sets of disc rolls. The serrations of these rolls bite into the upper and lower surfaces of the veneers to draw the latter along the path. Either or both of the upper and lower sets of rolls is or are driven in any convenient manner.

Rolls 177 and 180 are serrated or toothed members which draw the veneers out of path 22. However, insead of rolls, chains extending longitudinally of the path and having teeth or pins projecting therefrom may be used in place of the rolls.

As stated above, first pressure means 165 and second pressure means 1'67 can be driven in any desired manner. However, these must be synchronized so that they operate at exactly the same speed. FIG. 1 diagrammatically illustrates one way of driving both pressure means. In this example, a chain 186 extends around sprockets 187 and 188 fixedly mounted on the shafts of rolls 170 and 171, and sprockets 190 and 191 fixedly mounted on the shafts of serrated rolls 177 and 180. This chain extends around sprockets 187 and 188 in order to drive them in opposite directions, and around sprockets 190 and 191 for the same purpose. Chain 186 also extends around an idler sprocket 194 and a sprocket 195 on the drive shaft of an electric motor 196. With this arrangement, the motor drives rolls 170 and 171 to feed the veneers into path 22, and the serrated rolls 177 and 180 to draw said veneers out of the path.

As each veneer moves into the nip 176 of pressure rolls 170 and 171, it is pressed substantially flat in a transverse direction, and is directed in this condition by entrance funnel 135 into path 22. Upper and lower wires 25 and 27 are closely spaced vertically so that they prevent any portions of the veneers from extending upwardly or downwardly very far relative to the path. Funnels 135, 65 and 64 direct any portions of the veneers that may spring out of the path back into said path. As the veneers pass between gun nozzles 13 and 17, they are sprayed with glue, and an even coating is applied to the upper and lower surfaces of the veneers because said surfaces are maintained substantially equidistant from the nozzles as they pass therebetween. The teeth of serrated rolls 177 and 180 bite into the upper and lower surfaces of the veneers to grip these surfaces without smearing or otherwise interferring with the glue on said surfaces.

FIG. 1 includes pairs of upper and lower serrated rolls 200, 201 and 202 arranged along a path 203 which is aligned with path 22 beyond the exit end thereof. These rolls are driven in any convenient manner, not shown, to move the veneers away from apparatus 10. If desired, rolls 201 and 202 may be driven at a faster speed than rolls 200 for quick removal of the veneers and for separting successive veneers from each other. In this case, serrated rolls 200, 201 and 202 would have over-riding clutches so that each set can be rotated at a faster speed than its normal driving speed.

The teeth or serrations of rolls 177 and 180 may be pin points, teeth projecting radially from the rolls or teeth inclined rearwardly with reference to the direction of rotation of the rolls. FIG. 6 illustrates serrated roll 177 with the latter type of teeth. In this example, the roll has teeth 207 which are inclined rearwardly relative to the direction of rotation of the rolls, said direction being indicated by arrow 208. This rearward inclination of the teeth permits said teeth to be withdrawn from the veneers without tearing the wood.

The operation of spraying apparatus 10 is apparent from the above description. The core veneers 20 are substantially flattened outby pressure rolls and 171 as they are moved into path 22 between wires 25 and 27. These wires maintain the veneers in this substantially fiattened condition while glue is sprayed onto the upper and lower surfaces thereof. The gun nozzles are stationary relative to path 22, and as the wires keep the veneers fiat as they pass between the nozzles, the glue is evenly applied to the surfaces of the veneers.

The steel wires 25 and 27 are of very small diameter, something of the order of 0.020 inch. These wires are of such small diameter that they do not affect the coating of the veneer surfaces. Being circular in cross section, the wires touch the veneer surfaces only along extremely thin lines, and the glue on the surfaces manages to cover these lines even while the veneers are moving along the path or immediately after they clear the wires. It is only the serrations or rolls 177 and that come into contact with the veneers as they leave the wires, and these rolls do not interfere with or affect the glue coating. In actual practice, it has been found that wires 25 and 27 may be separated a distance a little more than the thickness of the veneers. This enables the veneers to be moved more easily through the apparatus, but any wrinkles or upwardly or downwardly extending projections are kept substantially in the general plane of the path by the wires. It also has been found that spring loading the wires to permit a limit amount of longitudinal movement thereof, makes it' easier to move the veneers through the apparatus.

As veneers 20 are quitethin they sometimes split longitudinally' thereof either before or after entering apparatus 10. If veneers have one or more longitudinal splits positioned in alignment with a space or spaces between wires '25 and 27 as the veneers move along path 22, portions of the veneers may project into said space or spaces beyond said wires. Bottom 132 and top 133 of hoods 94 and 105 act as guide means extending transversely of the path and converging in the direction of movement of the articles along said path to press any such projecting portions of the articles back into the general flat plane thereof. Similar converging guide means are formed by trough 63 and adjacent edge 82 of wall 79, trough 62 and adjacent edge 81 of wall 78, and edges 141 and 142 of hood bottom 137 and hood top, 138. The guide means formed by edges 141 and 142 is particularly important since it is immediate? ly ahead of serrated rolls 177 and 180. This prevents any portions of the veneers that tend to project upwardly or downwardly out of the general plane of the veneers from being caught by the teeth of these rolls, thereby eliminating the possibility of said veneers being ripped longitudinally thereof with the consequent damage to the veneers and the apparatus, and the possibility of having to shut down the operation in order to clean out the mess.

Wires 25 and 27 are kept clean by the moving veneers. Inner shields 47 and 70 protect the upper and lower guns and their associated parts from the glue, and either direct any glue accumulating thereon back to the glue spray emerging from the nozzles or to the troughs at the bottom of the apparatus. Outer shields 53 and 71 confine the overspray, and glue accumulating on the inner surfaces of these shields is directed out of the apparatus by troughs 62 and 63 or troughs 86 and 87. Upper and lower hoods 93, 94 and 104, 105 trap the excess air from the spray nozzles, and this is exhausted out of the apparatus through pipes 98, 99, 119 and 120.

If-desired, only one set of spray nozzles may be used for spraying either the upper or the lower surfaces of the veneers being moved past them. For example, only upper guns 12 may be used, in which case, lower guns 16 would be omitted. If this were a permanent condition, the lower section 45 of casing 42 could be omitted, and the veneers moved over a suitable supporting surface. On the other hand, guns 12 can be omitted, and only guns 16 used.

What is claimed is:

1. Precision spraying apparatus for thin sheet-like articles that are liable to be deformed in wrinkles, comprising upper and lower supporting means defining a horizontal path along which sheet-like articles are to be moved, said upper and lower supporting means being spaced apart just sufficiently to enable said articles to move therebetween along the path while maintaining the articles substantially flat and to form an entrance at one end and an exit at the opposite end of the path, at least one of said supporting means comprising a plurality of laterally-spaced thin wires in a common plane and extending longitudinally of the path, the number of wires being suflicient to keep the article substantially fiat as it moves along said path, first pressure means near said entrance for gripping and flattening the articles to move them between the upper and lower supporting means, said supporting means being spaced sufliciently close together so that the articles which are substantially flat when they are directed to said path are maintained in that substantially fiat condition as said articles pass therebetween, maintaining the articles in the flattened state as said articles move therebetween, second pressure means adjacent said exit for gripping the articles to draw them from between the upper and lower supporting means, said first pressure means and said second pres sure means each comprising a pair of opposed article advancing surfaces, said surfaces being separated during operation of the device by a distance which is fixed and sub- 8 stantially the same as" the'distance between said supporting means, and spraying means adjacent-said wires to spray liquid between the thin wires and on to the articles as the articles as the latter are moved along said wires and the path, the 'wires'retaining the articlesat a fixed distance from the spraying means and being sufiiciently thin to. not affect the coating of liquid sprayed onto said article.

2. Precision spraying apparatus according to claim 1 wherein each of said upper and lower supporting means comprise a said plurality of thin wires.

3. Precision spraying apparatus according to claim 2 wherein said spraying means include first'spraying means adjacent the upper wires and second spraying means adjacent the lower wires. 4. Spraying apparatusas claimed in claim 3 in which said spraying means comprises at least one upper row of spray guns and at least one lower row of spray guns positioned at predetermined distances above and below said path and having nozzles spaced from and projecting towards the path,- said upper and lower gun rows extending transversely of the path. Y Y Y x 5. Spraying apparatus as claimed in claim 4 including inner shield means for each of said gun rows extending from the nozzles thereof in the direction away from said path to shield the guns from atomized liquid, and outer shield means for each of the lower and upper gun rows extending substantially from said path away therefrom and opening towards the path to confine liquid overspray rebounding from the articles moving along said path.

6. Apparatus as claimed in claim 5 including closed upper and lower hoods outside the upper and lower outer shield means above and below said path and opening towards the latter to trap excess air introduced during the atomization of the liquid, and exhaust means connected to said hoods for removing the entrapped air.

7. Apparatus as claimed in claim 6 including air jets in the upper and lower hoods arranged to provide aircurtains in said hoods to prevent atomized liquid from travelling from said outer shield means into the hoods.

'8. Spraying apparatus as claimed in claim 5 in which the upper outer shield means has side walls extending upwardly from lower edges near' said path, and including troughs formed along said lower edges of the side walls inwardly thereof. Y

9. Spraying apparatus as claimed in claim 8 in which the inner shield means of the upper row of guns is a shield substantially in the form of a V in cross section having side walls extending downwardly and inwardly towards the nozzles of said upper row of guns, whereby liquid can drain off said side walls into the atomized liquid being discharged by the nozzles.

10. Spraying apparatus as claimed in claim 5 in which the lower outer shield means has side walls extending downwardly from upper edges near said path, andincluding a trough means near lower edges of said side walls.

11. Spraying apparatus as claimed in claim 10 in which the inner shield means of the lower row of guns is a shield in the form substantially of an inverted V in cross section having side walls extending downwardly and outwardly towards the trough means of the lower outer shield, whereby liquid can drain off said side walls in to said trough means.

12. Spraying apparatus as claimed in claim '3 in which said upper and lower wires diverge from each other at the path entrance and in a direction opposite to the direction of movement of the articles to form a funnel at said entrance.

13. Spraying apparatus as claimed in claim 3 including guide means extending transversely of the path above and below said wires and converging in the direction of movement of the articles along the path to press any portions of the articles projecting into spaces between the wires above or below said wires back into the general flat plane of the articles. Y Y

14. Spraying apparatus as claimed in claim 3 in which said second pressure means comprises a set of upper toothed members and a set of lower toothed members, each set extending transversely of said path and one set being spaced from the other to enable teeth of the members to grip the lower and upper surfaces of the articles at the exit end of the path.

15. Spraying apparatus as claimed in claim 14 including guide means extending transversely of the path above and below said wires and converging in the direction of movement of the articles along the path to press any portions of the articles projecting into spaces between the wires above or below said wires back into the general flat plane of the articles, said guide means being positioned near said toothed members.

16. Spraying apparatus as claimed in claim 1 including spring means connected to each wire to permit the latter wire a limited amount of movement longitudinally of said path.

17. Spraying apparatus as claimed in claim 1 in which said first pressure means comprises upper and lower pressure rolls having resilient peripheral surfaces and a nip therebetween transversely aligned with the entrance of the article path.

*18. Spraying apparatus as claimed in claim 1 in which said second pressure means comprises a set of upper toothed members and a set of lower toothed members, each set extending transversely of said path and one set being spaced from the other to enable teeth of the members to grip the lower and upper surfaces of the articles at the exit end of the path.

19. Spraying apparatus as claimed in claim 18 in which the upper and lower toothed members comprise upper and lower sets of laterally-spaced serrated disc rolls.

20. Spraying apparatus as claimed in claim 18 in which teeth of said upper and lower toothed members are inclined in the direction opposite to the direction of movement of the articles along the path.

21. Spraying apparatus as claimed in claim 18 including guide means extending transversely of the path at said wires and inclined towards the Wires in the direction of movement of the articles along the path to press any portion of the articles projecting into spaces between the wires and beyond the latter back into the general fiat plane of the articles, said guide means being positioned near said toothed members.

22. Spraying apparatus as claimed in claim 1 including shield means around said spraying means and said upper and lower supporting members to confine liquid overspray from rebounding from the articles moving along said path.

23. Spraying apparatus as claimed in claim 25 including guide means extending transversely of the path at said wires and inclined towards the wires in the direction of movement of the articles along the path to press any portion of the articles projecting into spaces between the wires and beyond the latter back into the general flat plane of the articles.

24. Spraying apparatus as claimed in claim 1 in which said first pressure means and said second pressure means are spaced apart a distance less than the length of the shortest individual article to be sprayed.

References Cited UNITED STATES PATENTS 1,900,878 3/1933 Hopkins 35564 1,964,790 7/1934 Roberts 118326 X 2,779,690 1/ 1957 Gaiser 1l8---326 X 2,848,353 8/1958 Norris 1l8326 X 2,854,946 10/1958 Norris 118-326 X 2,986,149 5/1961 Van Brakel 13464 WALTER A. SCHEEL, Primary Examiner I. P. MCINTOSH, Assistant Examiner U.S. Cl. X.R. 1l8-326 

